topic Re: Troubleshoot slow performance in Operating System - Linux

Troubleshoot slow performance

Vittorio_3 — Tue, 19 Jul 2011 06:51:49 GMT

I have very slow resposne keying and clicking as well on my RH machine, what is the basic troubleshoot steps /command to see what is wrong, it's kind of general question for me as I'm trying to get big picture, what is the good source /ling to learn this,

I tried to find good book, but didn't found anything, they mostly refer to var/log files, and each *nix has its own log file structure,

Tx al

Re: Troubleshoot slow performance

Turgay Cavdar — Tue, 19 Jul 2011 08:27:11 GMT

You can start with using some basic tools: vmstat, sar, iostat, free, top

Re: Troubleshoot slow performance

Naj — Tue, 19 Jul 2011 11:25:07 GMT

HI,

Slowness issue is very very subjective issue and need take some time to investigate.
First of all, you might need to know what is your server main purpose then from there you can get some hints for next step.

logfile
The logfile is one of important resources for you to start troubleshooting.below is some basic log file

/var/log/*
/var/log/messages <-- one of famous logfile

Process
background process is importat part to check and you always can ask uncle google to get some useful script to execute in server.

Tools

Be good administrator doesn't mean memorize all the command but you must very smart how to choose and use the tools for solve the issue.

you can use the tools as said above

Hope can help you

Thanks

Naj

Re: Troubleshoot slow performance

Steven E. Protter — Tue, 19 Jul 2011 15:55:23 GMT

Shalom,

good advice posted thus far.

free

Most common causes of lack of system response:

Lack of free memory - causes processes to be paged in and out of memory to disk
I/O issues, to much heavy, application driven - can be driven by item 1
Applications hogging too much cpu - top can help identify.

SEP

Re: Troubleshoot slow performance

Arunabha Banerjee — Tue, 19 Jul 2011 17:02:08 GMT

Can you please share the following command output.

# cat /etc/redhat-release

# uname -r

# arch

# uptime

# free -mto

# vmstat 5 10

# iostat -c

# vmstat -S m

# top -bn 1

# cat /proc/cpuinfo

# cat /proc/meminfo

# df -hT

# fdisk -l | grep -i Disk

Re: Troubleshoot slow performance

Naj — Wed, 20 Jul 2011 03:21:07 GMT

Some useful command you may practice

See Every process running as user abc

[root@87$sdhj~]# ps -U abc -u abc u
USER       PID %CPU %MEM   VSZ RSS TTY      STAT START   TIME COMMAND
abc 15796 0.0 0.0 19728 2172 pts/0    S+   01:11   0:00 ssh abc@azpc.com
abc18352 0.0 0.0 37128 1644 ?        S    03:16   0:00 sshd: abc@pts/2
abc 18353 0.0 0.0 54004 1484 pts/2    Ss   03:16   0:00 -bash
abc 30678 0.0 0.0 37128 1740 ?        S    00:55   0:00 sshd: abc@pts/0
abc 30679 0.0 0.0 54004 1484 pts/0    Ss   00:55   0:00 -bash

Find Out top 10 CPU Consuming Process

# ps -auxf | sort -nr -k 3 | head -10

Find Out top 10 CPU Consuming Process

# ps -auxf | sort -nr -k 3 | head -10

ps -ef pid,ppid,vsz,args |sort -nbk 3 |tail -3

Thanks

Naj